Method of making alkaline magnesite.



UNTTE TATES PATENT OFFICE.

EMIL RUEFF, OF NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. 67 5,018, dated May 28,1901.

Original application filed August 3, 1898, Serial No. 687,595. Dividedand this application filed June 23,1899 Serial No. 721,616. (Specimens)To It ZUILOWY/ it m/(l/y concern.-

Be it known that I, EMIL RUEFF, a resident of the borough of Manhattan,city, county, and State of New York, have invented certain new anduseful Improvementsin Producing Alkaline Magnesite, of which thefollowing is a specification.

This application is a division of Serial No. 687,595, filed by me August3, 1898.

This invention relates to improvements in fireproofing and heat andsound insulating media, and has for its object to produce a method ofmaking a compouudsuitable to be used for building-blocks, boiler-coverings, and in like situations where a non-conducting fireproof compound isdesirable.

To this end the invention consists in the process hereinafter set forthand claimed.

In carrying out my invention I produce a compound of magnesia differentfrom the ordinary carbonate of magnesia of commerce in that it has agreater percentage of water than the said ordinary carbonate ofmagnesia. The carbonate of magnesia of commerce is either the lightcarbonate of magnesia, the heavy carbonate of magnesia, or the mineralmagnesite, the normal carbonate of magnesia MgO,OO The light carbonateof magnesia maybe said to have the following two formuhe:

which latter formula also represents the composition of heavy carbonateof magnesia of com merce, The basic or alkaline carbonates which Iproduce contain more water and are in part indicated by the followingformulae:

This new carbonate of magnesia I shall hereinafter designate as alkalinemagnesite.

In producing alkaline magnesite I may proceed in various ways. One wayto produce alkaline magnesite is as follows: I mix one part of powderedcalcined magnesite with twenty parts of water and conduct to suchmixture while in a state of agitation carbonicacid gas under a pressureof about twentyfive pounds per square inch, until the mixture hasabsorbed less than one part, by Weight, of the carbonic-acid gas, so asto prevent the formation of a normal carbonate of magnesia (MgO,CO orany of its hydrates. The whole mass is then heated gradually to atemperature less than or preferably to about 160 Fahrenheit, drained,dried, andv may then be compressed under a pressure of from two hundredto one thousand pounds per square inch into the desired shape. Thearticle thus obtained is a carbonate of magnesia which contains lesscarbonic acid and more chemically-bound water than any othercorresponding commercial carbonate of mag nesia heretofore produced. Thealkaline magnesite thus obtained differs from the ordinary magnesite inthat it contains in proportion to its magnesia less carbon dioxid thanordinary magnesite and also in that it contains chemically-combinedwater which is not present in ordinary magnesite. The 01- dinarymagnesite is a heavy and dense mineral, while the article which Iproduce is a very finely divided and light product which forms porouslumps in the presence of water.

The excess of chemically-bound water and the method of preparing themass vastly improves the condition of the substance. It is very light inweight, and, unlike all other articles of the same class, it possessesgreat tensile strength and elasticity and is able to withstand not onlythe roughest handling, but also the severest test to which any buildingmaterial used for lining interior walls, ceilings, the. may besubjected. This substance has great resistance to the influence of heatand may be used for fireprooiing, and being a non-conductor of sound maybe also used as an insulating-lining for covering walls, ceilings,ice-boxes, safes, 860., and may be used as a pipe or boiler covering.This substance, which I have callec alkaline magnesite, is claimed by mein another application for patent filed August 7, 1899, Serial No.726,409.

What I claim, and desire to secure by Letters Patent,'is-- 1. Theherein-described process of producing alkaline magnesite containing anexcess of chemically-bound water which consists in acting upon calcinedmagnesite in the presence of water with less carbon dioxid than isnecessary to produce a normal carbonate, heating the mass at atemperature not higher than 160 Fahrenheit and drying the mass andfinally compressing it into the desired form.

2. The herein-described process of producing alkaline magnesitecontaining less carbonic acid than corresponding normal magnesite and anexcess of chemically-bound water which consists in mixing one part ofcal- EMIL RUEFF.

Witnesses:

CHARLES E. SMITH, lVIAURIGE BLOOK.'

